This invention relates generally to means for providing a low friction roller bearings, and more particularly to an improved rigid roller frame for low friction tracking devices for a roller bearing.
Roller bearings are ideally suited for many types of equipment, particularly for traveling blocks, swivels, rotary drives and the like. One type of roller bearing cage or frame construction provides end plates that are held together in spaced apart relationship by rigid bars which also maintain the spacing between adjacent rollers. A complement of rollers is placed within the frame. The cage or frame is positioned between inner and outer roller races where the rollers are in rolling contact with the bearing surfaces of both inner and outer races. The ends of the rollers exert axial thrust against the frame end plates causing friction. In addition, when the bearing is being used the rollers tend to skew or become slightly misaligned resulting in poor performance.
The roller must be restrained axially to maintain proper alignment with the inner and outer races and to prevent excess wear to the roller ends and the end plates. There should be as little friction as possible. A bearing frame having a concave seat in the end plates of the rigid frame and a spherical ball inserted between the roller end and the concave seat in the end plate has been previously used. While this arrangement has the benefit of somewhat lower friction, the hardened steel balls between the flat end of the roller and the frame seat lessen wear at the ends of the rollers but do not provide the means to maintain the rollers in alignment. In roller bearings having tapered or conical rollers there has been provided a cage having different sized, spaced-apart end plates held together by rigid bars, and frusto-conical roller bearings having rollers provided at each end with radial elongated ball seats and balls seated in the ends of each roller as well as seated in elongated seats in each end wall. However, such cages, because the ball seats are elongated, do not provide for accurate piloting of the rollers.
The foregoing illustrates limitations known to exist in present roller bearings. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter.